Rem Koolhaas is the official genius behind the architectural firm OMA. But when OMA designed the Seattle Central Library, the name whispered behind the scenes was Joshua Prince-Ramus. Last year, the dashing young Prince-Ramus (a 36-year-old Seattle native) split up with Koolhaas—and took the old lion's entire New York staff with him. He's here to talk about his new firm REX, collaboration, hyperrationalism, and ongoing plum projects, including a Kentucky museum and a Texas "theater machine." (Seattle Central Library, 1000 Fourth Ave, 386-4636. 6:30 pm, $12 adv/$15 at the door.) JEN GRAVES